1. Field of the Invention
The present invention relates to an outside-vehicle monitoring system for recognizing a three-dimensional object forward of a vehicle and particularly relates to an outside-vehicle monitoring system for recognizing a pedestrian forward of the vehicle with high precision.
2. Description of the Related Art
Hitherto, various types of outside-vehicle monitoring systems for recognizing the environment forward of a traveling vehicle have been proposed for supporting and controlling the driving of the vehicle, for example. Japanese Unexamined Patent Application Publication No. 5-265547 discloses an example of technology for processing a couple of images picked up by a couple of CCD cameras (a stereo optical system), calculating the distance distribution over the entirety of both images, grouping the distance-distribution data into a plurality of units, and comparing the grouped distance distribution units to three-dimensional road-shape data, three-dimensional object data, and so forth that had already been stored, so as to recognize roads and three-dimensional objects forward of the vehicle.
It is especially demanded that the outside-vehicle systems data representing the pedestrian with high precision from recognized data representing other three-dimensional objects, so that during driving contact is avoided between the vehicle and the pedestrian with increased reliability by using a driving-support control system or the like. However, according to the technology disclosed in the above-described Patent Application Publication, the pedestrian data extraction is performed on the basis of the width, height, and so forth of a recognized three-dimensional object in three dimensions. Therefore, it was difficult to extract pedestrian data with sufficient precision.
For solving the above-described problem, for example, Japanese Unexamined Patent Application Publication No. 2000-329844 discloses a technology for recognizing the pedestrian by having the pedestrian carry a predetermined portable transmitter-receiver with him/her for shifting the frequency of a received radar signal by as much as a predetermined period and transmitting the shifted frequency, and by transmitting and receiving radar signals between the vehicle and the portable transmitter-receiver through an on-board transmitter-receiver.
However, according to the above-described technology, it is necessary that all pedestrians carry the above-described portable transmitter-receiver with them, so that all of the pedestrians forward of the vehicle can be recognized.